The invention relates to a system for performing a given data transmission between a transmitter and a receiver such as a system which is used for remote operation of a door lock of an automobile, for example.
A system which operates a door lock of an automobile as by an electronic key is proposed in the prior art. In a system of this type, the electronic key is associated with an emitter which produces a given identification signal while a receiver is disposed on the part of the automobile so that a given unlocking operation takes place upon reception of the predetermined identification signal by the receiver.
When such system is modified to enable a remote operation, it is necessary that a power supply associated with the receiver be maintained on in order to enable its operation whenever the electronic key is operated. Specifically, while the electronic key or the emitter may be provided with a power switch, for example, which may be turned on whenever it is desired to operate the key, the system cannot be operable unless any power switch provided on the receiver is maintained on.
It is to be noted that a system of the type described must be capable of receiving and decoding a complex identification signal in order to prevent a theft, thus resulting in a complex arrangement of the receiver with consequent increase in the power dissipation. Hence, if the receiver is maintained in a condition to be fed from the power supply when the engine of the automoible is deactivated, the battery mounted on the automobile will be super-discharged, and may disable the starting of the engine in worst cases.